Flow process for conjugating unconjugated unsaturation of fatty acids

Abstract

A flow process for conjugating unconjugated unsaturation of fatty acids in the presence of alkali metal hydroxide under at least autogenic pressure at elevated temperature with control of the cis/trans to trans/trans ratio of the conjugated fatty acid product.

What is claimed is: 
     
       1. A flow process for conjugating unconjugated unsaturation of fatty acids in feedstock containing same and controlling the cis/trans to trans/trans ratio of the resulting conjugated fatty acid product in the presence of requisite aqueous alkali metal hydroxide for providing a minor proportion of free alkali in the resulting reaction mixture, and the dissolution of the resulting alkali metal soap in the aqueous phase of said reaction mixture which comprises: continuously charging said feedstock, said alkali metal hydroxide, and water into a flow reaction zone maintained under at least autogenous pressure;   therein heating the resulting reaction mixture to a temperature of about 200° to 370° C.;   continuously withdrawing from said zone the crude product stream when the unconjugated fatty acid value therein has been reduced to practically zero and the cis/trans to trans/trans fatty acid ratio of said crude product stream is between about 50:1 and 0.1:1;   acidulating the crude product stream, thereby springing crude fatty acid product; and   recovering said crude fatty acid product.   
     
     
       2. The flow process of claim 1 wherein said unconjugated fatty acids comprise linoleic acid, linolenic acid, and mixtures thereof. 
     
     
       3. The process of claim 2 wherein said feedstock is a glyceride oil. 
     
     
       4. The process of claim 1 wherein said feedstock is a mixture of fatty acids containing said unconjugated fatty acids. 
     
     
       5. The flow process of claim 1 wherein a soap is formed from said fatty acids and said alkali metal hydroxide, and said soap is the feedstock charged into said zone. 
     
     
       6. The flow process of claim 1 wherein said feedstock comprises partial esters of said fatty acids and polyol. 
     
     
       7. The flow process of claim 6 wherein said polyol is glycerol. 
     
     
       8. The flow process of claim 6 wherein said polyol is glycol. 
     
     
       9. The flow process of claim 1 wherein said feedstock comprises alkyl esters of said fatty acids. 
     
     
       10. The flow process of claim 1 wherein said feedstock contains about 30 to about 80% by weight of said unconjugated fatty acids. 
     
     
       11. The flow process of claim 1 wherein said alkali metal hydroxide is sodium hydroxide. 
     
     
       12. The process of claim 1 wherein about 1 to about 20% stoichiometric excess of said alkali metal hydroxide is charged into said zone. 
     
     
       13. The flow process of claim 1 wherein the proportion of water in said reaction mixture is about 40% to about 85% by weight. 
     
     
       14. The flow process of claim 1 wherein said reaction mixture is heated to about 220° to 330° C. 
     
     
       15. The flow process of claim 14 wherein said temperature is about 250° to 300° C. 
     
     
       16. The flow process of claim 1 wherein the residence time of said reaction mixture in said zone is from about 1 to about 40 minutes. 
     
     
       17. The flow process of claim 1 wherein the cis-trans to trans-trans fatty acid ratio of said crude product stream is about 2.5:1. 
     
     
       18. The process of claim 1 wherein said recovered crude fatty acid product is refined. 
     
     
       19. The flow process of claim 18 wherein said refining step includes dehydration of said recovered crude fatty acid product under vacuum and distillation of said dehydrated crude fatty acid product.